diff --git a/arch/arm64/mm/init.c b/arch/arm64/mm/init.c index 2475bbe5a..0f321d131 100644 --- a/arch/arm64/mm/init.c +++ b/arch/arm64/mm/init.c @@ -59,6 +59,15 @@ static void __init reserve_crashkernel(void) } #endif +/* + * The main usage of linux,usable-memory-range is for crash dump kernel. + * Originally, the number of usable-memory regions is one. Now there may + * be two regions, low region and high region. + * To make compatibility with existing user-space and older kdump, the low + * region is always the last range of linux,usable-memory-range if exist. + */ +#define MAX_USABLE_RANGES 2 + #ifdef CONFIG_CRASH_DUMP static int __init early_init_dt_scan_elfcorehdr(unsigned long node, const char *uname, int depth, void *data) @@ -228,9 +237,9 @@ early_param("mem", early_mem); static int __init early_init_dt_scan_usablemem(unsigned long node, const char *uname, int depth, void *data) { - struct memblock_region *usablemem = data; - const __be32 *reg; - int len; + struct memblock_region *usable_rgns = data; + const __be32 *reg, *endp; + int len, nr = 0; if (depth != 1 || strcmp(uname, "chosen") != 0) return 0; @@ -239,22 +248,36 @@ static int __init early_init_dt_scan_usablemem(unsigned long node, if (!reg || (len < (dt_root_addr_cells + dt_root_size_cells))) return 1; - usablemem->base = dt_mem_next_cell(dt_root_addr_cells, ®); - usablemem->size = dt_mem_next_cell(dt_root_size_cells, ®); + endp = reg + (len / sizeof(__be32)); + while ((endp - reg) >= (dt_root_addr_cells + dt_root_size_cells)) { + usable_rgns[nr].base = dt_mem_next_cell(dt_root_addr_cells, ®); + usable_rgns[nr].size = dt_mem_next_cell(dt_root_size_cells, ®); + + if (++nr >= MAX_USABLE_RANGES) + break; + } return 1; } static void __init fdt_enforce_memory_region(void) { - struct memblock_region reg = { - .size = 0, + struct memblock_region usable_rgns[MAX_USABLE_RANGES] = { + { .size = 0 }, + { .size = 0 } }; - of_scan_flat_dt(early_init_dt_scan_usablemem, ®); + of_scan_flat_dt(early_init_dt_scan_usablemem, &usable_rgns); - if (reg.size) - memblock_cap_memory_range(reg.base, reg.size); + /* + * The first range of usable-memory regions is for crash dump + * kernel with only one region or for high region with two regions, + * the second range is dedicated for low region if exist. + */ + if (usable_rgns[0].size) + memblock_cap_memory_range(usable_rgns[0].base, usable_rgns[0].size); + if (usable_rgns[1].size) + memblock_add(usable_rgns[1].base, usable_rgns[1].size); } void __init arm64_memblock_init(void)